The Dream Argument and the Student Who Concluded Nothing Exists
An 18-student first-year reading group meets for 50 minutes on Descartes' First Meditation. The tutor has two translations of the text and a handout containing the phrase 'I think, therefore I am'. Student A argues that the dream argument proves that nothing exists. Student B replies that the dream argument is 'just psychology' and contains no philosophical argument. No secondary commentary is allowed in the session. The tutor must lead the group to a defensible reconstruction, but several students are already using the phrase 'radical scepticism' loosely. The room has a whiteboard, the two translations, and no laptops. The tutor wants students to distinguish the method of doubt from a metaphysical conclusion before they write their first essay.
1. Reconstruct the dream argument in premise-conclusion form and identify its conclusion. Does it conclude that nothing exists?
Read the worked answer
A defensible reconstruction: P1: The senses sometimes deceive us about small and distant things. P2: There are no definitive marks by which I can distinguish waking experience from dreaming. P3: If I cannot rule out that I am dreaming, then any belief based on the senses can be doubted. C: Therefore, sensory-based beliefs lack certainty and should not be accepted as indubitable. The conclusion is epistemic: sensory beliefs are dubitable. It is not the metaphysical conclusion that nothing exists. To infer 'nothing exists' from 'I can doubt the senses' is a non sequitur; doubt is compatible with the existence of the external world. Student A has converted a methodological suspension of assent into a positive denial.
2. Explain the methodological role of hyperbolic doubt and why Student B's 'just psychology' reading misses it.
Read the worked answer
Hyperbolic doubt is a deliberate device, not a report of actual psychological uncertainty. Descartes exaggerates the grounds for doubt - dreams, and later an evil demon - in order to suspend assent to anything that is not absolutely certain. The aim is to find a foundation that cannot be doubted, from which other knowledge might be rebuilt. Student B's 'just psychology' reading treats the dream argument as a description of mental states and ignores its justificatory function. The argument is a thought experiment designed to test which beliefs survive extreme sceptical pressure. Whether Descartes was personally anxious is irrelevant to the validity of that test. The psychological reading also makes the cogito unintelligible, since the cogito is supposed to be the point at which the method of doubt reaches its limit.
3. Assess whether the cogito answers the dream argument. What does it establish and what does it not establish?
Read the worked answer
The cogito establishes that, while I am thinking, I exist as a thinking thing. Even if I am dreaming, there is a thinking subject having the dream; the act of doubting itself presupposes a doubter. So it answers the dream argument only in the narrow sense that it secures the existence of the thinker. It does not establish the existence of the body, the external world, or other minds. Descartes needs further argument - notably a proof of God's existence and non-deceiving nature - to validate clear and distinct perceptions and to recover the external world. The cogito is therefore a foundation, not a complete refutation of scepticism. Students should not say 'I think, therefore everything exists'; the inference is far more limited.